146958-06-7Relevant articles and documents
Syntheses, Crystal Structures, and Optical Properties of the Hexagonal Perovskites Variants ABX3 (B = Ni, A = Gu, FA, MA, X = Cl, Br; B = Mn, A = MA, X = Br)
Daub, Michael,Ketterer, Ines,Hillebrecht, Harald
, p. 280 - 287 (2018)
Herein we report on our systematic investigations on the solution processed synthesis and characterization of transition metal halides (guanidinium, formamidinium, and methylammonium nickel bromides and chlorides as well as methylammonium manganese bromide) with the composition ABX3 (A = organic cation; B = Mn, Ni; X = Cl, Br). The investigations were carried out with respect to possible applications of 3d transition metal compounds for the perovskite solar cell. All the compounds represent different variants of the hexagonal perovskite structure (2H). Crystal structures and symmetry relations are discussed. Additionally, (CH3NH3)2MnI4, which consists of tetrahedral coordinated Mn2+, and the water containing compounds (CH3NH3)MnBr3·2H2O, which forms chains of edge sharing octahedra, as well as (CH3NH3)NiCl3·2H2O, which consists of dimers of octahedra, are presented. Investigations on the crystal structures are supported by vibrational and optical spectroscopy.
Adjusting the Introduction of Cations for Highly Efficient and Stable Perovskite Solar Cells Based on (FAPbI3)0.9(FAPbBr3)0.1
Liu, Guozhen,Zheng, Haiying,Zhu, Liangzheng,Alsaedi, Ahmed,Hayat, Tasawar,Pan, Xu,Mo, Li'e,Dai, Songyuan
, p. 2436 - 2443 (2018)
Although the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has increased to 22.7 %, the instability when exposed to moisture and heat has hindered their further practical development. In this study, to gain highly efficient and stable perovskite components, methylammonium (MA), Cs, and Rb cations are introduced into a (FAPbI3)0.9(FAPbBr3)0.1 (FA=formamidine) film, which is rarely used because of its poor photovoltaic performance. The effects of different contents of MA, Cs, or Rb cations on the performance of (FAPbI3)0.9(FAPbBr3)0.1 films and devices are systematically studied. The results show that the devices with Cs cations exhibit markedly improved photovoltaic performance and stability, attributed to the clearly enhanced quality of films and their intrinsic stability. The (FAPbI3)0.9(FAPbBr3)0.1 devices with 10 % Cs show a PCE as high as 19.94 %. More importantly, the unsealed devices retain about 80 % and 90 % of the initial PCE at 85 °C after 260 h and under 45±5 % relative humidity (RH) after 1440 h, respectively, which are better than that with 15 % MA and 5 % Rb under the same conditions. This indicates that a highly efficient and stable perovskite component has been achieved, and PSCs based on this component are expected to promote their further development.
Efficient solar cells with enhanced humidity and heat stability based on benzylammonium-caesium-formamidinium mixed-dimensional perovskites
Liu, Guozhen,Zheng, Haiying,Xu, Xiaoxiao,Zhu, Liangzheng,Alsaedi, Ahmed,Hayat, Tasawar,Pan, Xu,Dai, Songyuan
supporting information, p. 18067 - 18074 (2018/10/02)
Perovskite solar cells (PSCs) exhibit remarkable photovoltaic performance with a power conversion efficiency (PCE) over 22%, but they exhibit instability in moist environments and at high temperatures. Compared to 3D perovskites, two-dimensional (2D) layered perovskites display excellent environmental stability but relatively poor photovoltaic performance. Here, we combined 2D/3D perovskites and simultaneously introduced the cesium cation (Cs+) to fabricate benzylammonium-caesium-formamidinium mixed-dimensional (MD) perovskite (BE/FA/Cs MD perovskite) solar cells. The BE/FA/Cs MD perovskite device with an optimal benzylammonium content exhibits a PCE as high as 19.24%. The improved PCE of 19.24% (BE/FA/Cs MD, x = 0.05) is attributed to great crystal orientation, outstanding surface quality, superior optical properties and enhanced charge transfer. More importantly, the BE/FA/Cs MD perovskite devices display superior humidity and heat stability. When subjected to 50% relative humidity (RH) for 1600 h and 85 °C for 240 h in the dark, the BE/FA/Cs MD (x = 0.05) devices without encapsulation retain 85% and 83% of their initial PCE, respectively. These results provide us with an important method to obtain highly efficient MD PSCs with long-term stability as a next-generation photovoltaic energy source.